Classifier for flour-mills.



]. P. STOFFEL;

CLASSIFIER FOR FLOUR MILLS.

APPLICATION men JAN. 11, 1916.

1,223,005. Patented A r .17; 1917.

r onms PETERS 00.. Pnoro-nrna. WASHING ran. a. c

JOHN P. STOFFEL, or LOS ANGELEVS, CALIFORNIA.

CLASSIFIER FOR FLOUR-MILLS.

I Specification of Letters Patent.

Application filed January 11, 1916. Serial No. 71,433.

sitter screensand for directing and regulating the movement of granular material thereover.

It is the object of this invention to provide a mechanism for separating and grading the stock and flour obtained by subjecting grain to the crushing action of milling rollers, which embodies a plurality of superposed grading screens or sieves having meshes of such different degrees of fineness and so arranged in relation to each other that the ground materials may be separated into various classes, according to their degree of granulation, such as fine, medium and coarse stocks, and flour.

Another object is to provide an arrangement of the screens in a gyrating sifter which will permit of the ready delivery of the several grades of the granular materials from one screen to another and to separate points of discharge.

The principal object is to provide means for vibrating the sifter'screens independent of the movement of the screen in its entirety so as to facilitate the passage of the finer granular materials therethrough and thus serve to prevent clogging of thescreen, thereby effecting arapid screening and separating action.

A further objectis to provide adjustable means for controlling themovement of the materials carried on the var ous screens to prevent the material from accumulatlng excessively at pointson the screen surface and for spreading the coarser materials over the screens in layers not in excess of a-predetermined depth.

A further objectis to provide a shuttle vibrator of simple construction which is automatic in its operation and adapted to be attached to most gyrating or reciprocal sifting screens now generally in use for the purpose of agitating the screens and the materials thereon independent of the screen frames. 1

Another object is to provide a simple and effective means whereby the distributing flights or Spreaders may be adjusted and retained in various positions to regulate the depth of materials on the screens.

Other objects will appear hereinafter.

The invention is illustrated in the accompanying drawings in which:

Figure 1 is a view in section and elevation illustratlng the construction of the lateral shuttle vibrator.

Fig. 2 is a view in section and elevation showing the adjustable flight or obstructor.

Fig. 3 is a view in perspective of the shuttle vibrator support and impact member.

Fig. 4: is, a view illustrating the shuttle vibrator as mounted on the under side of a screen.

Fig. 5 is an enlarged detail section and elevation illustrating the manner of holding the adjustable flight in various positions.

Fig. 6 is a detail of the stationary obstructors carried by'one'of the screens.

Fig. 7 is a view in perspective of a modified form of the shuttle vibrator.

The essence of the present invention resides in means for vibrating bolting screens 30. used in flour mill machinery, independent of their frames so as to reduce clogging of the screens to a minimum, and also in flights for regulating the spreading of the materials over the screens. As the granular character of the materials varies throughout the diflerent screens, itis deemed necessary toprovide several forms of :Vibrators and flights on the difi'erent screens according to the nature of the material being worked. In this case I have illustrated the screens as provided with transverse vibrators, one of which is shown in detail in Fig. 1. This vibrator consists of areciprocal shuttle or bar 53 which is slidably supported adjacent its ends in brackets 54 and arranged transversely of the screen. The brackets 54: are spaced a suitable distance apart and are secured to the screen in any desired manner. While the brackets may be of various constructions. they are here shown as formed of wire, as illustrated in Fig. 6"; the wire be: ing'bent to form a spring coil 55 through which the shuttle vibrator 53 slidably eX- tends. The ends ofthe coil 55 terminate in log members 56 which are looped at their ends to receive bolts or other fastenings by which the brackets are held in place. The

shuttle 53 is of a length greater than the Patented Apr. 17,1917.

space between its supporting brackets and Fig. 1 if desired, but are here illustrated in Fig. 3 as carried by stationary flights 59 i which are secured to the screen 32 and extend transversely thereof. The longitudinal shuttles 58 are slidably carried by the flights 59 and are of such length as to be capable of reciprocal movement in relation to the flights so that when they are moved longitudinally by the impulse given thereto by movement of the classifier, shoulders 60 on the ends of the shuttles 58 will strike the igh'ts59 with sufiicient force to vibrate the screen 82. lVhile I have shown the vibrators as arranged above the screens, it is manifest that they may be disposed on the under side thereof, as illustrated in Fig. 4 and while the vibrators are shown as extending transversely and longitudinally of the screens it is obvious that they may be placed to extend diagonally and that their number and arrangement may be varied as occasion requires.

It is to be noted that the brackets or supports for the shuttle vibrators are attached to the screen and not to the screen frames so that the force of impact of the shuttles is delivered to the screens independent of their frames.

The adjustable flights shown on the screen are illustrated in detail in Figs. 2 and 5. The flights consist of depending blades or plates 61 which are rigidly mounted on stems 62, reciprocally and revolubly mounted in the frames. The outer ends of the stems 62 project beyond one of the side rails ofthe screen frames and are formed with hand-holds 63 by means of which they may be shifted longitudinally or turned laterally. As a means for normally maintaining the stems 62 in their outermost position, collars 64 are formed on the stems and springs 65 arranged to bear between the collars and a stationary part of the frame. The plates 61 forming the flights extend within a short distance of the upper faces of the screens .when the flights are in their normal vertical position. When it is desired to adjust the spacing between the flights and the screen the stem 62 is moved inwardly and turned in either direction to dispose the flight in the desired position. The stem is then retracted to position the flight blade between a pair of spaced pins 66 on the screen frame, as shown in Fig. 5, which pins, in engaging the opposite sides of the flight blade, serve to hold the latter against turning movement. The spring 65 then operates to maintain the flight in engagement with the pins.

The number and arrangement of the flights may be varied as circumstances demand and they may be used in conjunction with stationary flights if desired.

In the movement of the granular materials across the several screens, they are caused to havea spiral path of travel, and therefore have a tendency to accumulate along one wall of the screen frame or its partition. The flights are provided for preventing this accumulation and also to cause the materials to spread evenly over the screens at a depth not exceeding a predetermined point; the depth of the layer of materials on the screens being regulated by adjusting the flights. The gyratory movement of the classifier operates to reciprocate the shuttle vibrators which on striking their supports transmit a vibrating shaking action to the screens, tending to loosen such particles of the granular materials as clog the screen mesh, thus hastening the action of the classifier and lessening the amount of attention ordinarily required in maintaining the screens clean.

In Fig. 7 I have illustrated a modified form of the shuttle vibrator and brackets,

the latter being formed with wire and having a pair of loops 67 arranged side by side and the shuttle bar consisting of wire bent to return on itself to pass through the loops. In this construction the bend 68 of the wire forms a shoulder which strikes the brackets on reciprocation of the shuttle.

While I have shown the screens as divided longitudinally, it is manifest that such division maybe dispensed with in some in-- stances. It is obvious that various changes may be resorted to and the parts differently arranged in relation to each other without departing from the spirit and scope of the invention as set forth in the following claim.

What I claim is:

In a classifier, a screen, a pair of spaced brackets affixed to said screen, a bar reciprocally mounted in said brackets, and shoulders on the outer ends of said bar adapted to alternately strike said brackets on reciprocal. movement of the bar, said bar being adapted to be reciprocated on shaking of the screen.

In testimony whereof I have signed my name to this specification.

copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

